Moss & Lichen Treatment

Moss treatments are designed to kill the plant spores that will break through your paint or roof coatings and cause premature corrosion

No matter where you are in the country, moss, mould and lichen growth is inevitable and it shouldn’t be left unchecked because it can be quite destructive. Plant spores start small and they embed themself to cladding and membrane surfaces, putting down root into whatever it can. As the plants grow their root structures get stronger and practically eat into thin-film paint coatings and membrane layers. Eventually, they will expose the bare steel, encourage rust and in the long term severe corrosion and even holes. Moss & Lichen grow freely on Skylights – especially older material and can be particularly difficult to remove if it is left too long.

A soft wash application of a specialist broad-spectrum disinfectant is usually enough to keep it at bay, it is the most cost-effective means of cleaning a surface and it has long-lasting effects.

In some regions it is more important to treat surfaces more often – higher rainfall areas in certain parts of the North Island and West Coast of NZ mean growth is more prevalent, but it still grows very well in dryer areas like the middle of the South Island.

What is Moss Spray made of?

Moss treatments are usually a Benzylamonium Chloride solution sprayed on to your roof or walls at a specific dilution rate suited for the level of growth. Once the solution has done its work the natural weathering process gently takes the decomposing material away over time. Our operators are trained in the correct procedures for chemical treatments, including disconnecting rainwater collection systems prior to treating your roof.

This method of cleaning is sometimes described as Soft-Washing or Chem-washing and while mostly used on roofs – it can also be successfully applied to wall cladding, patios, car parks, fences and any structure that attracts moss.

Alder Building Wash Services Moss & Lichen Treatment - Hot Water Pressure Application on Light Moss Layers Closeup
Light layers of moss can be removed quickly with Hot water pressure cleaning. The heat is effective in killing spores. This is a good option if you need an instant result.
Typical spray and leave application
Commercial roofs should be sprayed every 2 years on average
Unchecked moss growth behind a parapet

Moss and Lichen treatment frequency will vary depending on the level of soiling and re-growth, in some regions we recommend alternating Moss treatments and Chemical washing each year to get the best results.
Typically we recommend treatment every 2 years on steel roofs and every 12 months on membrane or tile roofs.